在英语语法中，动名词短语常常被用作主语。当一个句子的主语是由两个或多个动名词短语组成时，这些短语需要用并列连词连接起来。
例如：
- Swimming and hiking are my favorite outdoor activities.
- Reading, writing, and speaking English are essential language skills.
- Singing and dancing are popular forms of entertainment.
需要注意的是，这些并列的动名词短语应该在语法上保持一致。也就是说，它们应该以相同的形式出现，例如都是动词的-ing形式，或者都是不定式形式。
例如：
- Running, jumping, and playing basketball are all ways to stay active.
- To read, to write, and to speak English fluently are my goals.
此外，应该注意到并列的动名词短语不能改变句子的主语。主语应该是由这些短语所表示的动作或活动。
例如：
- Eating a balanced diet, exercising regularly, and getting enough sleep are important for maintaining good health. (正确)
- A balanced diet, regular exercise, and enough sleep are important for maintaining good health. (错误)
总之，当我们使用并列的动名词短语作为主语时，我们需要确保它们在语法上保持一致，并且不能改变句子的主语。这样可以帮助我们更加准确地表达我们的意思。
